1. Field of the Invention
This invention relates to hydrotherapy jets.
2. Description of the Related Art
Various hydrotherapy jets have been developed for use in spas, hot tubs, pools and bath tubs that discharge a stream of water that can be aerated through a variety of discharge nozzles. Designs of these hydrotherapy jets provide different flow characteristics that result in different massage effects being experienced by the body. Such jets have been found to produce a pleasing massage effect for many users, and have become quite popular. In the design of single or multi-use spas or tubs, it is common to use a variety of different jet nozzles to provide a variety of different massaging effects.
Early jets simply discharged a stream of warm water along the longitudinal axis of the jet body, with later jets providing aeration of the water stream. Since then numerous jets have been developed in which the direction of the stream can be adjusted. For example, U.S. Pat. No. 5,269,029 to Spears, et al. (assigned to the same assignee as the present invention) discloses a jet that provides an off axis stream of water and has an axial push-pull mechanism used to control the flow of water. The mechanism can also be rotated to rotate a stream of water around the jet axis, thus providing directional control over the stream.
Jets have also been developed having a rotating outlet or eyeball that automatically rotates in response to water flowing through the outlet. As an example, see Waterway Plastics, Inc., “1999 product catalog,” page 4, including part nos. 210-6120 and 210-6510. In these jets, the outlet can be adjusted off the jet's longitudinal axis to provide a turning moment in the eyeball in response to the water stream flow.
U.S. Pat. No. 6,178,570 to Denst et al. (assigned to the same assignee as the present invention) discloses a jet having a rotating eyeball with one or more discharge outlets that can be adjusted to vary the direction of the outlet flow stream, as well as the direction and speed of the eyeball's rotation. A high-pressure water stream flows through the outlets and, depending on the orientation of the outlets, the eyeball can rotate clockwise or counter-clockwise at different speeds.
U.S. Pat. No. 5,920,925 to Dongo (assigned to the same assignee as the present invention) discloses a jet having a rotating eyeball and a cap formed with a number of openings positioned at a common radius from the center of the cap. The jet produces a high-pressure water stream that flows through the eyeball, causing it to rotate at a high speed and discharge the jet in a circular pattern that impinges on the openings. Together, the rotational speed and the opening design produce the sensation of a number of simultaneously pulsating water streams that are directed into the spa.
Various hydrotherapy jets have been developed in the past for use with spas, hot tubs, and bath tubs that discharge an aerated stream of water through a variety of discharge nozzles. In general, such jets produce a constant flow stream that provides a good therapeutic effect. However, in an attempt to enhance the therapeutic effect, several systems have been designed that produce a pulsating flow. These systems have met with varying degrees of success as they often require additional or larger components, which increase system cost and add complexity, or generate unwanted pressure losses, thus requiring a larger pump than would otherwise be required.
One prior art approach has been to use mechanical devices to pulse water flowing to an individual jet, or a series of jets. An example of such a system is described in U.S. Pat. No. 4,320,541 to John S. Neenan. In this approach a series of mechanical blocking devices are used to intermittently block and unblock a flow stream. As a flow stream is unblocked, a pulse of water is sent to the jet and ultimately to the user. While this approach does provide a pulsating effect, blocking and unblocking of the flow stream causes abrupt pressure increases imposing a strain on spa systems. Aside from these drawbacks, such systems require additional components that add complexity, cost and weight. In addition, since the pulsation effect is generated away from the jet, the pulsed flow stream experiences a pressure loss, resulting in a decreased pulsation effect being felt at the jet exit.
In an alternate approach, rather than using mechanical devices to generate a pulsed flow, a hydraulic pumping device is used. In such a system, pulsation is produced by a distribution valve which houses a rotor that is rotated by inlet water flow, and distributes the inlet water to a series of outlets which are connected into the individual jets. The rotor is formed with a groove that sequentially aligns the water outlets to the water inlet so that each outlet is periodically connected to, and then disconnected from, the inlet. The water is supplied into each jet in a pulsating or chopping manner. Examples of this system are given in the U.S. Pat. Nos. 5,444,879 and 5,457,825 to Michael D. Holtsnider and assigned to Waterway Plastics, Inc. the assignee of the present invention.
While hydraulic systems do provide a degree of pulsation, they too suffer from many of the same problems as mechanical systems. For example, as the pulsation effect is generated away from the jet, the pulsed flow stream experiences a pressure loss which results in a reduced pulsation effect at the jet, and like the mechanical systems the additional componentry adds complexity, cost and weight to the system. Also, a larger water pump may be required to provide additional energy to rotate the rotor and to compensate for additional pressure losses.
To overcome the drawbacks associated with mechanical and hydraulic pulsed systems, pulsation systems have been designed that do not require mechanical devices or hydraulic distribution systems. Such systems generally have individual pulsation mechanisms located within the individual jets. Examples are shown in the Waterway “1997 product catalog,” page 1, deluxe and octagon series pulsating jet, and in U.S. Pat. No. 5,657,496 to Corb et al., also assigned to Waterway Plastics, Inc. The individual jets contain rotational devices commonly called eyeballs. The eyeballs have water conduits which discharge water flowing through the jet into the spa or tub. The conduits are angled to cause the eyeball to rotate and distribute the flow stream in a circular pattern. The circular distribution provides, to some degree, the sensation of a pulsed flow as the flow stream interacts with a specific point on the body in a periodic fashion. However, this is not truly a pulsed flow since the user actually experiences a continual flow stream, but in a circular pattern.
Attempts have been made to produce a jet that would produce a true pulsed flow. To this end, several designs have been developed in which pulsation is created at the jet itself. In these systems the flow stream at the jet is blocked periodically to create the sensation of a pulsed flow. See Waterway Plastics, Inc. “1997 product catalog” page 1, Standard Poly jets whirly and pulsator jets, and U.S. Pat. No. 4,508,665 to Spinnett. While both the Waterway and Spinnett Jet designs do in fact produce a pulsed flow, the pulsating is created by blocking the flow stream exiting the discharge member as it rotates past a blocking member. When the flow stream comes in contact with the blocking member the flow is temporarily interrupted or halted, thus generating a pulsed flow that is circular or spiral in nature, moving from one zone to another in a sequential manner. The blocking, however, creates an undesirable backflow into the jet, causing strain on the spa system and ultimately lowering efficiency. In addition, the Spinnett design requires multiple deflections of the flow stream as it passes through the jet, causing pressure losses and lowering the system efficiency.